1221332101 has 4 divisors (see below), whose sum is σ = 1332362304. Its totient is φ = 1110301900.

The previous prime is 1221332093. The next prime is 1221332111. The reversal of 1221332101 is 1012331221.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 1012331221 = 11 ⋅92030111.

It is a cyclic number.

It is not a de Polignac number, because 1221332101 - 2³ = 1221332093 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221332111) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 55515085 + ... + 55515106.

It is an arithmetic number, because the mean of its divisors is an integer number (333090576).

Almost surely, 2^1221332101 is an apocalyptic number.

1221332101 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1221332101 is a deficient number, since it is larger than the sum of its proper divisors (111030203).

1221332101 is a wasteful number, since it uses less digits than its factorization.

1221332101 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 111030202.

The product of its (nonzero) digits is 72, while the sum is 16.

The square root of 1221332101 is about 34947.5621610435. The cubic root of 1221332101 is about 1068.9184929293.

Adding to 1221332101 its reverse (1012331221), we get a palindrome (2233663322).

The spelling of 1221332101 in words is "one billion, two hundred twenty-one million, three hundred thirty-two thousand, one hundred one".